Hair Loss in Dogs

Dog hair loss is typically an obvious condition and can occur at any age, in any breed, and anywhere on the body. A variety of patterns and symptoms may develop depending on the underlying cause:

• Overall thinning of the hair
• Hair loss around eyes and mouth
• Patches of complete hair loss
• Symmetrical patterns of hair loss in the same place on both sides of the body
• Foul odor
• Itchiness
• Black or dark grey skin under hair loss
• Dry, scaly skin around area of hair loss
• Red, inflamed skin around area of hair loss
• Oozing moisture or bleeding around area of hair loss (typically a secondary condition)

Some possible causes for dog hair loss include:

• Pressure sores
• Friction (from a collar, for example)
• Nervous chewing or licking
• Trauma and/or scarring
• Post-surgical clipping
• Infection (bacterial, yeast or fungal)
• Ringworm (fungal infection)
• Allergies (fleas, food, environmental, contact)
• Mites (Mange)
• Abnormality in growth of the hair shaft
• Thyroid disorder
• Cushing’s disease
• Sex hormone imbalance
• Chemotherapy
• Skin cancer
• Genetics (certain breeds can develop hair loss in adulthood on ears, chest, thighs, or in certain pigmented parts of the body)

If your pet is experiencing hair loss, they should be examined by a veterinarian to determine the underlying cause and treat the condition. Diagnosis is based on the onset of signs, pattern of hair loss, skin condition around hair loss and whether the pet is itching or uncomfortable.

• Pattern of hair loss

  - Generalized hair loss could be a sign of mange or bacterial infection. Patches of hair loss could indicate conditions like ringworm, bacterial infection, mites, or mange. Hair loss in the rump and tail base area is often due to a flea allergy. Hair loss from the paws and face is sometimes environmental allergies (atopy). Symmetrical hair loss could be a sign of adrenal gland disorder, thyroid disorder, or abnormal sex hormone levels (endocrine disorders).

• Blood profile

  - Blood testing will help to diagnose certain immune system conditions, hormone abnormalities, thyroid disorders, Cushing’s disease, and Diabetes mellitus.

• Biopsy

  – If skin cancer or a tumor is suspected, or in persistent unresponsive skin lesions, the veterinarian may want to send a sample of the affected area to the laboratory to determine diagnosis and treatment.

• Skin impression smears

  – Pressing a microscopic slide on the affected area and analyzing it can show the presence of bacteria, yeast, or inflammatory cells.

• Skin scraping

  – Scraping the skin gently with a blade to gather hair follicles onto a slide can help detect the presence of mange mites.

• Luminescence

  – Some ringworm species will glow a fluorescent green-yellow under ultraviolet light.

• Allergen elimination trials

  – Feeding a hypoallergenic diet, treating fleas, or eliminating the use of certain shampoos or drugs may reveal an allergy to a certain food.  

• Allergy testing

  - Skin and/or blood tests can narrow down the list of potential environmental allergens.

Depending on the diagnosis, a variety of treatments are available for dog hair loss.

1. Antibiotics

   (oral or topical) will treat bacterial infections.

2. Antifungals

   (oral or topical) can treat yeast and ringworm infections.

3. Steroids

   may be required to treat certain skin conditions.

4. Immunosuppressive Drugs or Anti-cytokine Drugs

   may be needed for environmental allergy (Atopy) control. Often life long treatment is needed.

5. Immunotherapy

   may be needed orally or by injection for allergy desensitization.

6. Behavioral medications

   can treat nervous chewing or licking.

7. Medicated shampoos

   or dips can treat cases of mange.

8. Hypoallergenic diets

   will often solve hair loss due to food allergies. Allergies to foods take some time to define. The veterinarian will recommend a prescription or over the counter hypoallergenic diet and explain the proper method of transitioning to the new diet.

9. Monthly flea preventative

   can clear up hair loss associated with flea allergies

10. Thyroid medication and hormone therapy

    can reverse hair loss in hormonal and endocrine disorders.

11. Vitamin E, Vitamin A and fish oil supplements

    may be recommended for pets with certain conditions or a predisposition to dry skin or skin infections.

12. An Elizabethan collar

    (e-collar or cone) may be required to prevent your pet from licking at or itching the affected site until healed.

13. Surgery

    may be required to remove sections of skin cancer or tumors. Neutering or spaying your pet may be required for sex-hormone disorders.

Hair loss due to chemotherapy normally clears when chemotherapy sessions are completed. Hair loss may be permanent when caused by genetics, scarring, callouses or pressure sores. Most hair loss, when treated properly, will resolve. Recurrent skin conditions may require ongoing treatment.